1. Field of the Invention
The present invention relates to a hand operated chain block and, more particularly, to a hand operated chain block wherein a load sheave is rotationally driven by pulling a hand chain passing over a hand wheel, so as to wind up and down a load chain passing over the load sheave.
2. Description of the Prior Art
In general, a hand operated chain block of this type has a load sheave supported between a pair of side plates via bearings; and a hand wheel disposed at the outside of one side plate, so as to drive the load sheave through a drive shaft. A load chain with a load suspending hook passes over the load sheave, and a hand chain manually pulled passes over the hand wheel. The hand wheel is rotationally driven by pulling the hand chain to drive the load sheave via the drive shaft, so that the load chain is wound up and down to hoist up and down a load suspended from the hook.
With this conventional type of chain block, assembling the hand chain in the hand wheel requires the steps: that after a wheel cover for covering the hand wheel is removed from a chain block body, the hand wheel is disengaged from the drive shaft; and that after the removal of only the hand wheel from the chain block body, the hand chain is seated in the hand wheel and then the hand wheel is assembled back to the chain block body.
The conventional type chain block requiring the removal of the hand wheel from the chain block body for seating the hand chain in the hand wheel has disadvantage that the removal and assembling work is troublesome and also there is a fear that other components e.g. a mechanical brake may fall off together with the hand wheel, during the removal of the hand wheel from the drive shaft.
On the other hand, an attempt to assemble the hand chain in the hand wheel without removing the hand wheel from the drive shaft causes difficulties in downsizing the apparatus, because, stay bolts connecting the pair of side plates, which are usually projected at a radially outer side of the hand wheel to support the wheel cover, must be spaced apart from the outer periphery of the hand wheel with space required for the work of hooking the hand chain and thus cannot be located in the vicinity of the hand wheel.